The ASX Australian Share Ownership Study found that 6.48 million Australians held either direct (via listed vehicles) or indirect (via unlisted managed funds) share market investments in 2014.

The study did not measure share ownership through superannuation, other than via SMSFs.

The 36 per cent finding is a decline from 38 per cent when then study was last conducted in 2012.

"Despite the fall in overall ownership, the number of Australians holding shares directly-only remained stable at 26 per cent," said the ASX.

"More Australians are investing in international shares (13 per cent, up from 10 per cent in 2012); and portfolios are broadening to include other listed securities such as A-REITs, ETFs, options and bonds (5.6 per cent, up from four per cent in 2012)," said the ASX.

The study found Australian investors had a positive outlook about markets, with 54 per cent of direct investors saying they are likely to buy shares in the next 12 months.

The typical direct Australian shareholder is likely to be a tertiary-educated male, who trades predominantly through an online broker, said the ASX.

"Men are more likely to invest in shares, with 38 per cent of men being direct-share owners compared to 27 per cent of women.

"The likelihood of share ownership increases with age, with the 45- to 64-year age group having the highest portion of total (both direct and indirect) investors at 39 per cent," said the ASX.